Application of adsorptive process for desulphursation of fuel using coconut fiber as adsorbents

The presence of organic compounds with sulfur in fuels is one of the reasons for atmospheric pollution, since they liberate pollutants derived from sulfur such as oxides (SOX) when combusted in engines, which can affect both human health and the environment in a negative way. Removal of excessive sulfur from gasoline can be achieved through the process of adsorption, in which an adsorptive material captures the sulfur compound selectively. The development of more efficient and low-cost adsorbents to remove sulfur compounds has been improving, for instance, processes used in oil refining. Efficiency of desulfurization is correlated to the characteristics found in the adsorbent such as adsorption capacity, durability and regenerateness. This study aims to prepare coconut fiber impregnated with nickel and evaluate its adsorptive capacity of sulfur compounds such as the thiophene present in fuels. The utilized adsorbent was coconut fiber (mesocarp) obtained in the city of Quixada, state of Ceara, and the adsorbate was thiophene in n-hexane solution. During an adsorbent characterization test it could be observed that the number of proton charges in the surface of both natural and modified fibers is a function of pH. The materials showed adsorptive capacity of 35,0 mg.g(-1) of the sulfur compound. In the balance study, isotherm was best represented by the math model of Redlich-Peterson, which indicates heterogeneity in the adsorption sites. Adsorption kinetics was more adequate with the pseudo-second order model.